OK guys, here they are -- and they are big because when I tried to shrink 'em they got all cruddy.
Anyway, here is what I think. The LCM's sailed up/down various canals/rivers to pick-up points -- at this time they were in USN colors.
They were picked from the water & placed on DW for the trip to the Rhine, or some tributary thereof where they went back in the water.
At some point during the trip from shore to shore on the DW, they were repainted OD -- so you could show the LCM on a DW in USN colors or OD & be correct.
Anyway, to support my "not sure about red" comments from earlier, the first two pix show LCM on DW & you can see the bottom appears lighter than the side, so maybe it is just old scraped up & cruddy botton, who knows. I have not seen any neat pretty waterlines though.
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Now here are two Jolly Tars painting away at their LCM. Note again, the original color, seeming lack of red. And note how they are painiting down the whole side & even under the hull. Also note the lack of an airbrush, sanding sealer, body putty, etc, so one need not be too concerned with neatness here.
And lastly, this would appear to be a repainted LCM on a DW -- and I say that it is repainted only because it appears to be one solid color.
These pix are in my Gallery, Heavy Haulers Campaign, where I'm working my LCM on a DW project.
Hope all this helps. I've enjoyed the question & the discussion.
John
PS: Please note I'm not using words like "always", "never", etc -- I wasn't there & I'm not an expert. I suspect that if we could find pictures of every LCM hauled via DW, we would find many variations. But the photos I have, to include some not displayed above, are consistent with those displayed above.